This invention relates to improvements in communications line protectors, and more particularly to line protectors of the type that are located between central office switching equipment and inside switching-related equipment. The purpose of these line protectors is to protect the inside equipment from damage as a result of overvoltage and overcurrent conditions on the outside lines. One such line protector is shown in U.S. Pat. No. 4,168,515 issued Sept. 18, 1979, and the present invention is an improvement that is specifically directed to that line protector.
In telephone central offices where these protectors are located, they are typically mounted on a protector panel or connector board and with the protector devices being inserted into contacts on the board. The connector board is generally located at the juncture between outside plant lines and the central office equipment. Each protector unit generally serves the purpose of protecting both the tip side and the ring side of each line pair which are terminated on the connector panel. Generally speaking, the panel incorporates a test field so that electrical tests may be made on outside facilities or inside equipment in a convenient manner. Where a test field is not used or embodied on the connector panel, access for testing of the telephone pairs for each module may be conveniently accomplished by access holes in the module housing so that probes may be inserted into the housing for contact with the tip and ring circuits therein. One such arrangement is shown in U.S. Pat. No. 4,307,430 that issued Dec. 22, 1981. Rather than incorporating the features of U.S. Pat. No. 4,307,430, the present invention involves the novel modification of an existing commercial form of line protector as shown in U.S. Pat. No. 4,168,515, referred to above.